Home Forums Hunting & Shooting Ask The Gunwriters .300 Savage Load Data in .308 Win

Mule Deer, I’m going to develop a light hunting load using the 150gr Ballistic Tip in a .308. I’d like velocity to be around 2400-2500fps. I dug up an old post saying that .300 Savage data could be used. Given that the .300 Savage has less case capacity it seems reasonable to use this data directly. What do you think? It would give me more options than H4895 reduced loads.


Thanks.

Frank

Not MD by a long shot. Can’t match his experience, or knowledge, either.

Nothing wrong with H4895. Used it for several years to reduce recoil for my buddies sons and their friends. Finding a load that hits your criteria would be dead easy. Accuracy , in ever rifle we tried, was plenty good enough for a couple of hundred yards. If you’re reducing loads you’re not looking for a long range wonder anyway. We also did some with IMR 3031 and they worked out well. Don’t recall the loads and he has the notes.

If you want variety poke around a bit. Between powder companies , and bullet manufacturers, I found many loads that meet your criteria. Several IMR powders will do it.

As far as using 300 Savage data it may not work out all that well. There is quite a difference in case size. Pressures would be considerably lower in the 308 than the same load in the 300 Savage. Powders can do funny things when running at too low a pressure. Extreme velocity spread, poor accuracy, and burning dirtier than normal etc.

What stringnut said.

The easiest way to work up a lighter load for a cartridge is to look up the data for starting loads for THAT cartridge I just looked up the .308 in Hodgdon's on-line 150-grain data and the very first bullet listed is the 150 Ballistic Tip. The starting loads for two powders qualify: 39.0 grains of Benchmark for 2521 fps, and 37.0 grains of H322 for 2508 fps.

But you could also try 39.5 grains of H4895, or even less. The rule of thumb for single-based powders (all three mentioned are single-based) is that velocity varies directly with the weight of the powder charge.

As an example, with H4895 the maximum charge listed is 45.5 grains for 2870 fps. The listed starting load is 43.0 grains for 2742 fps, but according to Hodgdon H4895 can be used safely with loads down to 60% of the maximum load with no problems.

To arrive at a 2500 fps load, you divide 2500 fps by 2870 fps, which is 87% of the max load. For 2400 fps divide that by 2870, which amounts to 83.5% of max, still on very safe ground. The velocity numbers are all from a 24" barrel, so if your .308's barrel is the more common 22", the velocity would probably be 40-50 fps slower.

But because you're not trying to drastically reduce the load IM4895 or IMR4064 would also work.

If you don't have any of the powders mentioned the method can be easily applied to other extruded, single-based powders.

Here's how I would extrapolate down to 2500 fps using Hodgdon's H4895 data.

Hodgdon shows 45.5 grains for 2870 fps, and 43 grains for 2742 fps.

(2870-2742) / (45.5-43) = 128/2.5 = 51.2 fps per grain

Dropping from 2742 fps to 2500 fps is a decrease of 242 fps. At 51.2 fps per grain that's going to need a drop of 242/51.2 = 4.726 grains. Call it 4.7. So that puts the estimated charge at 43 - 4.7 = 38.3 grains.

https://loaddata.com/Home is your friend. Under 308 Winchester, see the listings for Hornady bullets, for target loads, and for the M1-A.

In their 10th edition manual, Hornady shows 308 Winchester Service Rifle loads that push 150s from 2,200 to 2,700 fps. Their loads for the 308 Winchester push 150s from 2,300 to 2,800 fps.

Lots of different powders to choose from in both places.


Okie John

Thanks for the replies.

Frank